1. Field of the Invention
The present invention relates to a closed rotary compressor mounted in, for example, an air conditioner or a freezing machine.
2. Description of the Prior Art
This kind of conventional closed rotary compressor 100 will be explained with reference to FIGS. 14 to 16. In each drawing, reference numeral 101 denotes a closed container in which an electric motor (for example, a DC brushless motor) 102 as an electric element is provided on the upper side and a compression element 103 driven to rotate by the electric motor 102 is accommodated on the lower side. The closed container 101 has a half-split structure composed of a cylindrical shell portion 101A whose upper end is opened and an end cap portion 101B whose upper end opening is closed above the shell portion 101A, and it is constituted by fitting the end cap portion 101B on the shell portion 101A to be closed by high frequency deposition and the like after accommodating the electric motor 102 and the compression element 103 in the shell portion 101A. Further, the bottom portion in the shell portion 101A of the closed container 101 is an oil bank B.
The electric motor 102 is constituted by a stator 104 fixed on the inner wall of the closed container 101, and and rotator 105 supported so as to be rotatable around a rotating shaft 106 inside the stator 104. The stator 104 is constituted by a stator core 174 configured by superimposing a plurality of stator iron plates having a substantially donut-like shape, and a stator winding (driving coil) 107 for giving a rotating magnetic field to the rotator 105 attached to a plurality of cog portions 175 formed on the internal periphery of the stator core 174 by the distributed winding method. The outer peripheral surface of the stator core 174 is brought into contact with and fixed to the inner wall of the shell portion 101A of the closed container 101.
In this case, a plurality of notches 176 are formed on the outer peripheral surface of the stator core 174, and the notch 176 is estranged from the inner wall of the shell portion 101A so that a passage 177 is formed in that space.
The compression element 103 includes a first rotary cylinder 109 and a second rotary cylinder 101 separated by an intermediate partition plate 108. Eccentric portions 111 and 112 driven to rotate by the rotating shaft 106 are attached to the respective cylinders 109 and 110, and the phases of these eccentric portions 111 and 112 are shifted from each other 180 degrees at the eccentric positions.
Reference numerals 113 and 114 designate a first roller and a second roller which rotate in the cylinders 109 and 110 respectively and turn in the cylinders by rotation of the eccentric portions 111 and 112. Reference numerals 115 and 116 denote first frame body and a second frame body, and the first frame body 115 forms a closed compression space for the cylinder 109 between itself and the partition plate 108 while the second frame body 116 similarly forms a closed compression space for the cylinder 110 between itself and the partition plate 108. Further, the first frame body 115 and the second frame body 116 respectively include bearing portions 117 and 118 which rotatably pivot the lower portion of the rotating shaft 106.
Reference numerals 119 and 120 represent cup mufflers which are disposed so as to cover the first frame body 115 and the second frame body 116, respectively. It is to be noted that the cylinder 109 communicates with the cup muffler 119 via a non-illustrated communication hole formed to the first frame body 115, and the cylinder 110 also communicates with the cup muffler 120 via a non-illustrated communication hole formed to the second frame body 116. Reference numeral 121 denotes a bypass pipe provided outside the closed container 101 to communicate with the inside of the cup muffler 120.
Reference numeral 122 denotes a discharge pipe provided above the closed container 101, and reference numerals 123 and 124 represent suction pipes leading to the cylinders 109 and 110. Moreover, reference numeral 125 designates a closed terminal which supplies power from the outside of the closed container 101 to the stator winding 107 of the stator 104 (a lead wire connecting the closed terminal 125 to the stator winding 107 is not illustrated).
Reference numeral 126 represents a rotator core of the rotator 105 which is obtained by superimposing a plurality of rotator iron plates punched out from an. electromagnetic steel plate having a thickness of 0.3 mm to 0.7 mm in a shape such as shown in FIGS. 15 and 16 and caulking them each other to be integrally layered.
In this case, the rotator iron plate of the rotator core 126 is punched out from the electromagnetic steel plate in such a manner that salient pole portions 128 to 131 constituting four magnetic poles, and reference numerals 132 to 135 represent concave portions provided so that salient pole portions are formed between the respective salient pole portions 128 to 131.
Reference numerals 141 to 144 denote slots into which a magnetic body 145 (a permanent magnet) is inserted. These slots 141 to 144 correspond to the respective salient pole portions 128 to 131 and formed on a concentric circle on the outer peripheral side of the rotator core 126 along the axial direction of the rotating shaft 106.
Further, reference numeral 146 designates a hole which is formed at the center of the rotator core 126 and to which the rotating shaft 106 is shrinkage-fitted.
Reference numerals 147 to 150 denote through holes having a size and a shape with which later-described rivets 151 for caulking are inserted. These through holes 147 to 150 are formed to be associated with the inner sides of the respective slots 141 to 144. Furthermore, reference numerals 161 to 164 represent air holes for forming oil passages formed between the respective through holes 147 to 150. After the multiple respective rotator iron plates are superimposed, they are caulked each other to be integrated, thereby forming the rotator core 126.
On the other hand, the magnetic body 145 is constituted by a rare earth magnet member such as a praseodymium based magnet or a neodymium based magnet whose surface is nickel-plated, and the outward form thereof is a rectangular shape as a whole with a rectangular cross section. The respective slots 141 to 144 have a size allowing insertion of the magnetic body 145 therethrough.
Reference numerals 166 and 167 denote tabular edge members attached to the upper and lower ends of the rotator core 126 and molded into a substantially discoid shape by using a non-magnetic material such as stainless or brass. Through holes are similarly formed to the edge members 166 and 167 at positions corresponding to the through holes 147 to 150.
It is to be noted that reference numeral 172 represents a discoid oil separation plate attached to the rotator 105 so as to be positioned above the edge member 166 and 173 designates a balance weight disposed between the plate 172 and the edge member 166.
With such a configuration, when the rotator winding 107 of the rotator 104 of the electric motor 102 is energized, the rotating magnetic field is formed to rotate the rotator 105. Rotation of the rotator 105 causes eccentric rotation of the rollers 113 and 114 in the cylinders 109 and 110 through the rotating shaft 106, and an intake gas absorbed from the intake pipes 123 and 124 is compressed.
The compressed high pressure gas is emitted from the cylinder 109 into the cup muffler 119 through the communication hole and discharged from a non-illustrated discharge hole formed to the cup muffler 119 into the closed container 101. On the other hand, the gas is emitted from the cylinder 110 into the cup muffler 120 through the communication hole and further discharged into the closed container 101 via the bypass pipe 121.
The discharged high pressure gas passes a gap in the electric motor 102 to reach the discharge pipe 122 and is discharged outside. On the other hand, although the oil is contained in the gas, this oil is separated by the plate 172 and others before reaching the discharge pipe 122 and directed to the outside by the centrifugal force. Further, it flows down to the oil bank B through the passage 177 and others.
As described above, in the conventional closed rotary compressor 100, since the rotating winding 107 constituting the stator 104 of the electric motor 102 adopts the distributed winding mode, the stator winding 107 relatively largely protrudes from the stator core 174 in the vertical direction as shown in FIG. 14. Therefore, the vertical dimension of the closed container 101 is also enlarged, thereby increasing the overall size of the closed rotary compressor 100.
In addition, since the gas within the stator 104 having the stator winding 107 of the distributed winding type is narrow as shown in FIG. 15, the flow velocity of the gas moving up therethrough becomes high. Moreover, the upper and lower ends of the concave portions 132 to 135 of the rotator 105 are closed by the edge members 166 and 167 or the plate 174, and hence the concave portions 132 to 135 does not contribute to suppression of the gas flow velocity either.
Since the oil is hard to be separated when the gas flow velocity is high, the oil easily flows out from the discharge pipe 122. Additionally, since the stator winding 107 stands up high outside of the plate 172 as shown in FIG. 14, the oil hardly flows to the passage 177 even if the centrifugal force acts, thereby reducing the oil separation effect.
Thus, the large space in the closed container 101 above the stator winding 107 of the stator 104 must be assured as shown in FIG. 14 in the prior art, which also encourages increase in the size of the closed rotary compressor 100.
On the other hand, in order to advance the flowing down of the oil into the oil bank B, an oil return passage 177 must be formed with the sufficient dimension. When a notch 176 is increased in size., however, the contact area between the outer peripheral surface of the stator core 174 and the closed container 101 (shell portion 101A) becomes small, and the strength of a part of the closed container 101 to which the stator core 174 is not in contact is lowered. Therefore, there occurs such a problem as that the closed container 101 is bent toward the inside at the notch 176. Thus, formation of the through hole at the outer peripheral portion of the stator core 174 irrespective of the notch can be considered, but the oil does not smoothly flow down as compared with that flowing on the inner wall of the closed container 101.
In order to solve the above-described technical problems in the prior art, an object of the present invention is to realize separation of the oil from the gas without any problem while downsizing the closed rotary compressor.
That is, the present invention provides a closed rotary compressor for accommodating in a closed container an electric element, and a rotary compression element driven by a rotating shaft connected to the electric element, wherein the electric element is constituted by a motor of the magnetic pole concentrated winding type comprising: a stator fixed to an inner wall of the closed container; a rotator rotatably supported by the rotating shaft inside the stator; a stator core constituting the stator; a plurality of cog portions and slot portions formed to the stator core; and a stator winding directly wound around the respective cog portions by utilizing the slot portions.
Further, when the rotary compression element is accommodated at a bottom portion in the closed container; the electric element is provided above the rotary compression element; a discharge pipe is attached on an upper wall of the closed container; a distance from the upper end of the stator winding of the electric element to the lower surface of the upper wall of the closed container is assumed as L1; and the vertical dimension of the stator of the electric element is assumed as L2, setting is made within a range of 0.3xe2x89xa6L1/(L1+L2)xe2x89xa60.6.
Furthermore, the rotator includes a rotator core; concave portions formed on the outer peripheral surface of the rotator core in the vertical direction; and edge members attached to the both upper and lower edges of the rotator core, notch portions being formed to the edge members at positions corresponding to the concave portions of the rotator core.
In addition, discharge holes formed to the cup muffler of the rotary compression element are provided, and through holes extending to the both upper and lower ends of the rotator are formed at positions corresponding to the upper part of the discharge hole of the rotator.
Further, a plurality of concave passages extending both upper: and lower ends are formed on the outer peripheral surface of the stator at predetermined intervals, cross sectional shape of each passage is formed so as to be narrow on the outer peripheral side of the stator and wide on the inner side of the same, and the outer peripheral surface of a part other than each passage is brought into contact with the inner wall of the closed container.
Moreover, the closed container is constituted by a shell portion whose one end accommodating the electric element and the rotary compression element therein is opened and an end cap portion for closing the opening of the shell portion and, assuming that a value thickness of the stator core of the stator of the electric element is SH and the distance from the stator core to the edge of the end cap portion is T, setting is made within a range of 0.15 less than T/SH less than 0.5 is set.
In addition, a passage area in the stator is set to be not less than 3.8% of the inside cross sectional area of the closed container.
Further, an area of a clearance in the stator is set to be larger than the area of the passage between the stator and the closed container.
Furthermore, the closed rotary compressor according to the present invention accommodates an electric element and a rotary compression element in a closed container, wherein the rotary compression element comprises: an intermediate partition plate; first and second cylinders provided on both sides of the intermediate partition plate; a rotating shaft which has eccentric portions whose rotating angles are shifted from each other 180 degrees and is extended in the axial direction of the closed container to be connected to the electric element; rollers fitted to the eccentric portions of the rotating shaft to rotate in the cylinders; and bearings for closing openings of the respective cylinders, and the electric element comprises: a stator which has a stator winding and is fixed to the closed container; and a rotator which is supported by the rotating shaft and rotatable on the inner side of the stator, gas emitted from the first cylinder being discharged toward the electric element, gas emitted from the second cylinder being discharged from the circumferential direction of the closed container into a space between the stator winding and the rotary compression element.
Additionally, a bypass pipe for guiding gas emitted from the second cylinder is provided to the outside portion of the closed container.
Further, the electric element includes a stator core constituting the stator; and a plurality of cog portions and slot portions formed to the stator core and is constituted by a motor of a magnetic pole concentrated winding type which directly winds the stator winding around the respective cog portions by utilizing the slot portions.